Game theory informs epidemic behavior

By Hallie Zolkower-Kutz

As Chicagoans battle this year’s flu season, researchers at Wake Forest University in North Carolina have been studying why some people get flu shots and others don’t, using unusual methodology: online gaming.

The study examined the decision-making process behind getting a flu shot as well as the factors that dissuade people from doing so. According to Brian Richardson, director of public affairs at the Chicago Department of Public Health, flu season has hit Chicago particularly hard this year, and the decision to get a flu shot is an important preventative measure, making the research especially relevant.

Frederick Chen, an economics professor at Wake Forest University and one of the researchers working on the study, decided to create a simple online game that imitates the spread of an infectious disease like the flu. The idea of using an online game originated because Chen was worried about the confines of using students as study participants.

“If I were to do this on campus, I’d be limited to the few thousand students here,” he said. “But if I were to go online, I’d have a much larger group of potential participants.”

The game mimicked a spreading epidemic by having players go through several rounds that represented days. As they played each round, participants had the option of spending points to take a self-protective action, like a flu shot. Then, based on the number of players and self-protective actions taken, a number of participants were “infected” with the virtual disease.

The goal for players was to earn the maximum number of points. Players who took no protective action and were not infected received the maximum number of points for that round, while those who took the protective action and avoided infection received fewer points. Some players were given the option of a low-cost protective measure, while others had only the option of paying a higher cost. This measure was put in place to represent the cost and incentive of getting a flu shot in real life. At the end of each round, players were informed of the total number of other players infected.

Researchers analyzed the data to determine which factors influence people’s decision-making during an epidemic.

The study showed that people were inclined to choose self-protective measures when the option was presented at a lower cost. It also indicated that knowledge of how many others are infected and the player’s past experience with the disease play a role in determining whether to get vaccinated.

The cost of the flu shot doesn’t always have to be monetary, according to Chen. He said there are other factors that alter the perceived cost of a flu shot. Aspects such as the time taken out of one’s day to get the shot and the fear of adverse side effects also have a role in the decision-making process.

Chen said the findings have important implications for policy-making in the future.

“We should try to think of policy that isn’t one-size-fits-all,” he said. “For some people, their perspective of the costs and benefits may differ. A more effective option would be to come up with different kinds of policies that would appeal to different groups of people.”

Chen said he thinks policies should decrease the price of flu shots and allow employees to take time off work to get a shot.

“Either we lower the cost, or we increase the benefit somehow,” he said.

Amanda Griffith, assistant professor of economics at Wake Forest and researcher with the study, found an increase in self-protective measures when more players were infected with the flu, a fact she said most likely means the spread of information is important during an epidemic.

“People really care about the prevalence around them,” she said. “It seems to really affect their behavior.”

Columbia student Thom Taglioli, an arts entertainment and media management major, has been urged by his family to get a flu shot, but he hasn’t gotten one this season.

“I actually haven’t gotten one in years, and I haven’t gotten the flu in years,” he said. “I think there’s too much of an emphasis on everyone getting [the flu shot] instead of telling us what it does or the side effects.”

Ruth Worock, the advance practice nurse at Columbia’s Health Center, has seen many students with flu-like symptoms. She said she believes spreading information about the flu would encourage people to get flu shots.

Chen said a flu shot is both beneficial to the person receiving it and helps stop the spread of infectious disease. As a teacher, Chen said he believes he is at a higher risk for getting the flu because he comes in contact with so many people daily, so he gets a flu shot every year.

“When you get a flu shot, you’re not just benefiting yourself, but other people as well,” Chen said. “If you don’t get sick, you can’t make other people sick.”